France's top prosecutor recommended on Monday that a probe be launched into corruption allegations involving Labour Minister Eric Woerth (photo), campaign financing for President Nicolas Sarkozy and the financial affairs of France's richest woman.

Prosecutor Jean-Louis Nadal said that while the case did not need to be referred to a court which tries serving ministers, it merited a politically independent investigation.

The prosecutor "recommends to the Versailles public prosecutor that the investigation continue within the framework of a preliminary investigation" carried out by an investigating magistrate.

The Versailles prosecutor, Philippe Ingall-Montagnier, will now decide whether Nanterre prosecutor Philippe Courroye, who has been accused of being close to Sarkozy and therefore not independent, should continue his own probe.

Calls have mounted for Courroye, who works for the justice ministry and therefore the government, to pass the case to an investigating magistrate, who is part of the judiciary and would have stronger powers.

Woerth is accused of obtaining a job for his wife from the man who manages Bettencourt's fortune, Philippe de Maistre, as well as helping the fund manager himself obtain France's top civilian honour.

An investigating magistrate would have more powers than a prosecutor, who can only carry out searches with the concerned party's agreement and has fewer options in terms of international cooperation.

What's more, lawyers do not have access to the prosecutor's preliminary investigations.

Woerth's lawyer, Jean-Yves Leborgne, told AFP that he was "satisfied" with the decision not to send the case to the Republic's Justice Court, but that he was "much more reserved" about the possibility of a preliminary investigation.

"A very dense probe has been under way for three months, I don't want everything to start from the beginning again with someone new," Leborgne said.